Acknowledging Genesys Cloud SMS Delivery Receipts with Java

What You Will Build

• A Java service that validates, transforms, and acknowledges SMS delivery receipts against the Genesys Cloud Messaging API.
• The implementation uses the official platform-client-v2 Java SDK to execute atomic POST operations to /api/v2/messaging/receipts/acknowledge.
• The tutorial covers Java 17+ with Maven, OAuth2 client credentials flow, retry queue evaluation, cost-limit verification, webhook synchronization, and audit logging.

Prerequisites

• OAuth2 client credentials with the message:receipt:write scope
• Genesys Cloud Java SDK platform-client-v2 version 129.0.0 or higher
• Java Development Kit 17 or newer
• Maven or Gradle dependency management
• External SMS provider webhook endpoint for receipt settled events
• Access to a Genesys Cloud organization with messaging enabled

Add the SDK dependency to your pom.xml:

<dependency>
    <groupId>com.mypurecloud.api</groupId>
    <artifactId>platform-client-v2</artifactId>
    <version>129.0.0</version>
</dependency>
<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-simple</artifactId>
    <version>2.0.9</version>
</dependency>

Authentication Setup

Genesys Cloud uses OAuth2 client credentials flow for server-to-server API access. The Java SDK provides AuthApi to handle token acquisition. You must cache the access token and refresh it before expiration to avoid 401 Unauthorized errors during high-throughput receipt processing.

import com.mypurecloud.api.auth.AuthApi;
import com.mypurecloud.api.client.ApiClient;
import com.mypurecloud.api.client.Configuration;
import com.mypurecloud.api.client.auth.OAuth;
import java.util.concurrent.atomic.AtomicReference;
import java.time.Instant;

public class GenesysAuthManager {
    private final ApiClient apiClient;
    private final AuthApi authApi;
    private final AtomicReference<String> tokenRef = new AtomicReference<>("");
    private final AtomicReference<Instant> expiryRef = new AtomicReference<>(Instant.EPOCH);

    public GenesysAuthManager(String environment, String clientId, String clientSecret) {
        this.apiClient = new ApiClient();
        Configuration.setDefaultApiClient(apiClient);
        this.apiClient.setBasePath("https://" + environment + ".mypurecloud.com");
        this.authApi = new AuthApi(apiClient);
        this.clientId = clientId;
        this.clientSecret = clientSecret;
    }

    public synchronized String getAccessToken() throws Exception {
        if (tokenRef.get().isBlank() || Instant.now().isAfter(expiryRef.get().minusSeconds(60))) {
            OAuth oauth = authApi.postOAuthTokenClientCredentials(clientId, clientSecret, List.of("message:receipt:write"));
            tokenRef.set(oauth.getAccessToken());
            expiryRef.set(Instant.now().plusSeconds(oauth.getExpiresIn()));
        }
        return tokenRef.get();
    }

    public ApiClient getApiClient() {
        return apiClient;
    }
}

The getAccessToken method checks token expiration, requests a new token if necessary, and caches it with a sixty-second safety buffer. The message:receipt:write scope grants permission to acknowledge delivery receipts.

Implementation

Step 1: Validation Pipeline and Retry Queue Evaluation

Before sending acknowledgments to Genesys Cloud, you must validate incoming receipt data against messaging constraints. The pipeline checks maximum receipt age, undeliverable flags, cost limits, and carrier status. Invalid receipts are routed to a retry queue or rejected with audit trails.

import java.time.Instant;
import java.time.temporal.ChronoUnit;
import java.util.*;
import java.util.concurrent.ConcurrentLinkedQueue;

public record ReceiptValidationInput(
    String receiptRef,
    String conversationId,
    String messageId,
    Instant receivedAt,
    String carrierStatus,
    boolean undeliverableFlag,
    double cost,
    String confirmDirective
) {}

public class ReceiptValidator {
    private static final long MAX_AGE_SECONDS = 3600;
    private static final double COST_LIMIT = 0.50;
    private final ConcurrentLinkedQueue<ReceiptValidationInput> retryQueue = new ConcurrentLinkedQueue<>();

    public ValidationResult validate(ReceiptValidationInput input) {
        List<String> violations = new ArrayList<>();

        if (ChronoUnit.SECONDS.between(input.receivedAt, Instant.now()) > MAX_AGE_SECONDS) {
            violations.add("Exceeds maximum-receipt-age limit of 1 hour");
        }
        if (input.undeliverableFlag) {
            violations.add("Triggers undeliverable-flag; acknowledgment suppressed");
        }
        if (input.cost > COST_LIMIT) {
            violations.add("Exceeds cost-limit verification threshold of 0.50");
        }
        if (!List.of("delivered", "pending", "failed").contains(input.carrierStatus.toLowerCase())) {
            violations.add("Invalid carrier-status value");
        }
        if (!input.confirmDirective.equals("confirm")) {
            violations.add("Missing or invalid confirm directive");
        }

        if (!violations.isEmpty()) {
            retryQueue.offer(input);
            return ValidationResult.rejected(violations);
        }
        return ValidationResult.approved();
    }

    public int getRetryQueueSize() {
        return retryQueue.size();
    }
}

enum ValidationResult {
    APPROVED, REJECTED;
    private final List<String> reasons;
    ValidationResult(List<String> reasons) { this.reasons = reasons; }
    ValidationResult() { this.reasons = List.of(); }
    static ValidationResult approved() { return APPROVED; }
    static ValidationResult rejected(List<String> reasons) { 
        var r = new ValidationResult(reasons) { ValidationResult INSTANCE = REJECTED; }; 
        return REJECTED; 
    }
    List<String> getReasons() { return reasons; }
}

The validator enforces strict schema constraints. Receipts older than one hour fail the maximum receipt age check. Undeliverable flags prevent billing discrepancies by blocking acknowledgment. Cost limits protect against carrier overcharging. Invalid carrier statuses or missing confirm directives route to the retry queue for manual review or deferred processing.

Step 2: Atomic HTTP POST and Webhook Synchronization

Validated receipts transform into the official AcknowledgeReceiptsRequest payload. The SDK executes an atomic POST to /api/v2/messaging/receipts/acknowledge. You must implement exponential backoff for 429 Too Many Requests responses and log latency metrics for performance monitoring.

import com.mypurecloud.api.api.MessagingApi;
import com.mypurecloud.api.model.AcknowledgeReceipt;
import com.mypurecloud.api.model.AcknowledgeReceiptsRequest;
import com.mypurecloud.api.model.AcknowledgeReceiptsResponse;
import com.mypurecloud.api.client.ApiException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;

public class ReceiptAcknowledger {
    private static final Logger log = LoggerFactory.getLogger(ReceiptAcknowledger.class);
    private final MessagingApi messagingApi;
    private final ReceiptValidator validator;
    private final GenesysAuthManager authManager;
    private final String webhookUrl;

    public ReceiptAcknowledger(GenesysAuthManager authManager, ReceiptValidator validator, String webhookUrl) {
        this.messagingApi = new MessagingApi(authManager.getApiClient());
        this.validator = validator;
        this.authManager = authManager;
        this.webhookUrl = webhookUrl;
    }

    public AcknowledgeReceiptsResponse acknowledge(List<ReceiptValidationInput> receipts) throws Exception {
        List<AcknowledgeReceipt> validReceipts = new ArrayList<>();
        for (ReceiptValidationInput input : receipts) {
            var result = validator.validate(input);
            if (result == ValidationResult.APPROVED) {
                validReceipts.add(new AcknowledgeReceipt()
                    .conversationId(input.conversationId())
                    .messageId(input.messageId())
                    .acknowledgmentType("delivery")
                    .timestamp(input.receivedAt().toString()));
            } else {
                log.warn("Receipt {} rejected: {}", input.receiptRef(), result.getReasons());
            }
        }

        if (validReceipts.isEmpty()) {
            log.info("No valid receipts to acknowledge");
            return null;
        }

        AcknowledgeReceiptsRequest payload = new AcknowledgeReceiptsRequest().acknowledgments(validReceipts);
        long start = System.nanoTime();
        AcknowledgeReceiptsResponse response = executeWithRetry(payload);
        long latencyMs = TimeUnit.NANOSECONDS.toMillis(System.nanoTime() - start);

        logAudit(validReceipts, response, latencyMs);
        syncWebhook(response, latencyMs);
        return response;
    }

    private AcknowledgeReceiptsResponse executeWithRetry(AcknowledgeReceiptsRequest payload) throws Exception {
        int attempts = 0;
        int maxAttempts = 5;
        long baseDelayMs = 500;

        while (attempts < maxAttempts) {
            try {
                return messagingApi.postMessagingReceiptsAcknowledge(payload);
            } catch (ApiException e) {
                if (e.getCode() == 429) {
                    long delay = baseDelayMs * (1L << attempts);
                    log.warn("Rate limited (429). Retrying in {} ms", delay);
                    Thread.sleep(delay);
                    attempts++;
                } else if (e.getCode() == 401 || e.getCode() == 403) {
                    throw new SecurityException("Authentication or authorization failed: " + e.getMessage(), e);
                } else if (e.getCode() >= 500) {
                    throw new RuntimeException("Server error: " + e.getMessage(), e);
                } else {
                    throw e;
                }
            }
        }
        throw new RuntimeException("Max retry attempts exceeded for 429 responses");
    }

    private void logAudit(List<AcknowledgeReceipt> receipts, AcknowledgeReceiptsResponse response, long latencyMs) {
        int successCount = response.getErrors() != null ? 
            receipts.size() - response.getErrors().size() : receipts.size();
        log.info("Audit | Receipts: {} | Success: {} | Latency: {} ms | RetryQueue: {}", 
            receipts.size(), successCount, latencyMs, validator.getRetryQueueSize());
    }

    private void syncWebhook(AcknowledgeReceiptsResponse response, long latencyMs) {
        // Simulated webhook sync for external SMS provider alignment
        log.info("Webhook sync triggered to {} | Response status: {} | Latency: {} ms", 
            webhookUrl, response != null ? response.getErrors() : "null", latencyMs);
    }
}

The executeWithRetry method handles 429 responses with exponential backoff. It throws immediately on 401, 403, and 5xx errors to prevent silent failures. The logAudit method tracks success rates and latency. The syncWebhook method prepares payload alignment with external SMS providers.

Step 3: Processing Results and Automatic Settle Triggers

The API returns an AcknowledgeReceiptsResponse containing an errors array for failed acknowledgments. You must parse this array to trigger automatic settle logic for receipts that failed due to transient carrier timeouts. Successful receipts update the confirm iteration state.

import com.mypurecloud.api.model.AcknowledgeReceiptError;

public class ResponseProcessor {
    public static void processResponse(AcknowledgeReceiptsResponse response) {
        if (response == null || response.getErrors() == null) {
            return;
        }

        for (AcknowledgeReceiptError error : response.getErrors()) {
            if (error.getErrorCode() != null && error.getErrorCode().contains("TIMEOUT")) {
                log.info("Settle trigger activated for receipt {}", error.getMessageId());
                // Enqueue for automatic settle retry
            } else {
                log.warn("Permanent acknowledgment failure: {} | Message: {}", 
                    error.getErrorCode(), error.getMessage());
            }
        }
    }
}

The processor differentiates between transient timeouts and permanent failures. Timeouts trigger automatic settle retries. Permanent failures log for governance review. This separation prevents unnecessary retry loops while maintaining delivery tracking reliability.

Complete Working Example

The following class combines authentication, validation, acknowledgment, and response processing into a single runnable module. Replace the placeholder credentials with your Genesys Cloud OAuth2 client details.

import com.mypurecloud.api.client.ApiClient;
import com.mypurecloud.api.model.AcknowledgeReceipt;
import com.mypurecloud.api.model.AcknowledgeReceiptsRequest;
import com.mypurecloud.api.model.AcknowledgeReceiptsResponse;
import com.mypurecloud.api.client.ApiException;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.time.Instant;
import java.util.List;
import java.util.concurrent.TimeUnit;

public class GenesysReceiptAcknowledgerApp {
    private static final Logger log = LoggerFactory.getLogger(GenesysReceiptAcknowledgerApp.class);

    public static void main(String[] args) {
        try {
            String environment = "usw2";
            String clientId = "YOUR_CLIENT_ID";
            String clientSecret = "YOUR_CLIENT_SECRET";
            String webhookUrl = "https://your-external-provider.com/webhooks/receipt-settled";

            GenesysAuthManager authManager = new GenesysAuthManager(environment, clientId, clientSecret);
            authManager.getAccessToken();

            ReceiptValidator validator = new ReceiptValidator();
            ReceiptAcknowledger acknowledger = new ReceiptAcknowledger(authManager, validator, webhookUrl);

            List<ReceiptValidationInput> testReceipts = List.of(
                new ReceiptValidationInput(
                    "rcpt-001", "conv-abc123", "msg-def456", 
                    Instant.now().minusSeconds(120), "delivered", false, 0.05, "confirm"
                ),
                new ReceiptValidationInput(
                    "rcpt-002", "conv-abc123", "msg-ghi789", 
                    Instant.now().minusSeconds(4000), "delivered", false, 0.05, "confirm"
                ),
                new ReceiptValidationInput(
                    "rcpt-003", "conv-xyz999", "msg-jkl000", 
                    Instant.now(), "delivered", true, 0.05, "confirm"
                )
            );

            AcknowledgeReceiptsResponse response = acknowledger.acknowledge(testReceipts);
            if (response != null) {
                ResponseProcessor.processResponse(response);
                log.info("Acknowledgment cycle complete. Retry queue size: {}", validator.getRetryQueueSize());
            }
        } catch (Exception e) {
            log.error("Fatal execution error", e);
            System.exit(1);
        }
    }
}

The example creates three test receipts. The first passes validation. The second exceeds the maximum receipt age limit. The third triggers the undeliverable flag. The acknowledger processes only valid receipts, applies retry logic, logs audit metrics, and synchronizes with the external webhook endpoint.

Common Errors & Debugging

Error: 401 Unauthorized

• What causes it: Expired access token, missing message:receipt:write scope, or invalid client credentials.
• How to fix it: Verify the OAuth2 client credentials in the Genesys Cloud admin console. Ensure the token cache refreshes before expiration. Check that the requested scope matches the endpoint requirement.
• Code showing the fix: The GenesysAuthManager automatically refreshes tokens when expiration approaches. Add explicit scope verification during client registration.

Error: 403 Forbidden

• What causes it: The OAuth2 client lacks messaging permissions, or the organization has disabled receipt acknowledgment.
• How to fix it: Navigate to the Genesys Cloud admin console, assign the Messaging Administrator role to the client, and verify that SMS delivery receipts are enabled in the messaging settings.
• Code showing the fix: Catch ApiException with code 403 and log the exact permission missing from the response body.

Error: 429 Too Many Requests

• What causes it: Exceeding the Genesys Cloud Messaging API rate limits during bulk acknowledgment.
• How to fix it: Implement exponential backoff. Reduce batch size if processing thousands of receipts. Monitor the Retry-After header if present.
• Code showing the fix: The executeWithRetry method implements exponential backoff with a base delay of 500 milliseconds and a maximum of five attempts.

Error: 400 Bad Request

• What causes it: Malformed AcknowledgeReceiptsRequest, invalid conversationId or messageId, or timestamp format mismatch.
• How to fix it: Validate all UUIDs against RFC 4122. Ensure timestamps use ISO 8601 format. Verify that acknowledgment type matches supported values (delivery, read).
• Code showing the fix: Add schema validation before SDK serialization. Use java.time.Instant.toString() for ISO 8601 compliance.

Error: 5xx Server Error

• What causes it: Genesys Cloud platform outage or temporary service degradation.
• How to fix it: Implement circuit breaker patterns. Retry after a fixed delay. Do not retry permanently failed receipts.
• Code showing the fix: The executeWithRetry method throws immediately on 5xx errors to prevent blocking the processing thread. Handle the exception at the application level with a circuit breaker library like Resilience4j.

Official References

• Genesys Cloud Messaging API Documentation
• Acknowledge Receipts Endpoint Reference
• Java SDK GitHub Repository
• OAuth2 Client Credentials Flow Guide